NEW evidence is being handed to Police Scotland and the Crown Office suggesting serial killer Angus Sinclair could be responsible for five unsolved murders in Scotland.

ITV investigator Mark Williams-Thomas said he was sending a report to Scottish law authorities which sets out all the evidence against Sinclair who was convicted of murdering four young girls.

It comes after Sinclair's ex-wife said she believed the World's End killer was responsible for the deaths of even more victims over "ten years of mayhem" in Glasgow.

READ MORE: Angus Sinclair found guilty of World's End murders

Mr Williams-Thomas, a former policeman said: “My report will go to Police Scotland and the Crown Office setting out all the evidence against Angus Sinclair in relation to five murders, one child rape and one robbery which I believe is enough to prosecute him for.”

HeraldScotland:

Mark Williams-Thomas

Sinclair, 73, was jailed for life and ordered to serve a minimum of 37 years in 2014 after a jury found him guilty of killing Christine Eadie and Helen Scott, both 17, in Edinburgh, in what became known as the World's End murders, because they were last seen leaving a pub by that name in the city's old town.

He was previously found guilty of killing Mary Gallacher in Glasgow.

The murderer was already behind bars for killing eight-year-old Catherine Reehill in Glasgow when he was sentenced to life.

HeraldScotland:

Mr Williams-Thomas's report comes after the airing of his TV series The Investigator: A British Crime Story in which he linked Sinclair to the unsolved murders of Anna Kenny, 20, Hilda McAuley, 36, and Agnes Cooney, 23 who were brutally abducted and killed within four months of each other in Glasgow in 1977.

Their killer has never been caught more than 40 years on but the show explored the possibility that Sinclair could be responsible.

READ MORE: Sinclair's wife secretly worked with World's End detectives

The investigator has also claimed the World’s End murderer teamed up with Thomas Ross Young to kill Frances Barker. The bakery worker vanished yards from her home in the city’s Maryhill in June 1977 and her body was later found dumped in Glenboig, Lanarkshire.

Thomas Ross Young was jailed for slaying Frances Barker, 37, but claimed before his death that  Sinclair was the real culprit.

HeraldScotland:

Angus Sinclair

Mr Williams-Thomas said: “My investigation shows that the manner in which the Glasgow three were killed bears all the hallmarks of the World’s End murders in Edinburgh – for which Angus Sinclair was convicted.

“I can place Sinclair or his caravanette at all three Glasgow crime scenes, which means I believe Sinclair could be responsible for the abduction of the women.”

READ MORE: World’s End murderer Angus Sinclair's secrets may die with him

Anna Kenny, 20, disappeared after a night out with a friend at the the Hurdy Gurdy bar in Townhead in August, 1977.

She left with a man and he later revealed to police that she left him to get a taxi home.

HeraldScotland:

She was missing for two years before her body was discovered in a shallow grave near Skipness on Kintyre.

In October 1977, the body of Hilda McAuley was found covered by bushes at Langbank, near the M8 motorway. The mum-of-two was last seen leaving the Plaza ballroom with a smartly dressed man.

Her body was discovered by kids out picking blackberries near a “lover’s lane”.

Two months later children’s nurse Agnes Cooney, 23, was found stabbed in woodland near Caldercruix, Lanarkshire. She had walked four miles from The Cladda Club in the South Side to an M8 sliproad and then hitched a lift to her home in Coatbridge.

Mr Williams-Thomas claims he has proof Sinclair and Thomas Ross Young  were involved in the the murder of Frances Barker 41 years ago — and once shared a house in Glasgow.

Sinclair lived with his mum on the same street as Frances Barker.

The ex-police officer said: “We’ve spoken to two people who told us Sinclair and Young lived together close to where Frances was.

“It’s the first time a direct link’s been made between them.

“And it supports my theory that Young didn’t kill Frances alone — his accomplice was Sinclair.”

He added: “Most of Sinclair’s killings point to a helper being involved, and Frances’s murder bears the unique hallmarks of five others we believe he committed that year.”

Sinclair’s ex-wife Sarah also took part in her first ever TV interview for the show where she claimed the killer was responsible for “10 years of mayhem” killing women around Glasgow.

HeraldScotland:

With her identity hidden, she said: "Angus started going back and forward to Edinburgh every weekend. He was going to do extra work painting and decorating. 'I don't believe that he ever stopped. They seem to think he had a period of time he went on a spree."

Sinclair was 25 when he married Sarah, then Hamilton, from Townhead in Glasgow in 1970. She was 20 and a trainee nurse.

They had met two years prior, just after Sinclair had served six years for the culpable homicide of his eight-year-old neighbour Catherine Reehill in Glasgow.

Police Scotland said that they have been working with the production team behind the show.

READ MORE: World's End killer's wife tells of 'kind' husband

A spokeswoman said: “Police Scotland has had ongoing engagement with the production team of ITV The Investigator as they have carried out research.

HeraldScotland:

“ITV The Investigator has indicated that they may have new information, witnesses or evidence in these cases, therefore we have requested details of the new witnesses and accompanying evidence in order that we can fully explore these matters.”

A spokesman for the Crown Office added: “The Crown can only bring criminal proceedings where there is sufficient credible, reliable and admissible evidence in law to justify bringing a case to trial. As with all cases, we will carefully consider any new evidence that comes to light.”